Chinese patent application No. 201320785583.4 discloses a liquid storage device of a cotton-free electronic cigarette, the liquid storage device has a simple structure, a strong connection and an easy assembly method over prior arts. The liquid storage device of the cotton-free electronic cigarette comprises a liquid storage cup for storing cigarette liquid, and a liquid percolation piece having a plurality of liquid percolation holes; wherein the liquid storage cup has a cylindrical shape, an inner wall of a liquid outlet end of the liquid storage cup is provided with at least two locking members, the liquid percolation piece has a circular edge which engages with an internal circumferential surface of the liquid outlet end of the liquid storage cup, the liquid percolation piece is inserted into the liquid outlet end of the liquid storage cup and is passed through the at least two locking members to be locked. Preferably, a filter piece is placed between the liquid percolation piece and the locking members and abuts against the liquid percolation piece; a heating element of a vaporization assembly is close to the liquid percolation piece and the filter piece. However, when cigarette liquid filled in the liquid storage device passes the liquid percolation piece to be absorbed by the filter piece, the filter piece filled with the cigarette liquid will easily become soft and deformed, as a result the deformed filter piece would fall off and separate from the liquid percolation piece which leads to the leakage of the cigarette liquid. The leaked cigarette liquid that has not been fully vaporized would be inhaled into a user's mouth, which greatly decreases the user's experience.